Abstract: To study the effect of telomerase-antisense oligonucleotide on the induction of apoptosis of hepatocellular carcinoma cell line and its mechanism. MethodsWe used HCC cell line SMMC-7721 as a target and cell line L-02 as the normal. Using the TRAP-ELISA we quantitively and qualitatively studied telomerase activity. We detected the apoptosis of HCC cell induced by telomerase antisense oligonucleotide through TUNEL stain,morphology and DNA electrophoresis.The phase analysis was performed by flow cytometry. We also used Western blot to study the expressing of cell cycle proteins. Results Telomerase-antisense oligonucliotide at proper concentration can obviously inhibit the telomerase activity of hepatocellularcarcinoma cell line and induce apoptosis after the cell were passageed for 23 to 26 times. The apoptosis is related with the expressing of cell cycle proteins. ConclusionTelomerase - antisense oligonucleotide can inhibit the telomerase activity of hepatocellularcarcinoma cell line and induce its apoptosis.